Glossary of Terms and Abbreviations

Alligation: A mathematical process used to calculate needed quantities of ingredients when compounding two or more products to obtain a desired concentration

Apothecary Measurement System: Measurement system for weighing drugs and solutions which uses both Roman and Arabic numerals together with fractions to identify parts of the unit of measure. To express an amount less than one, fractions are used.

Body Surface Area (BSA): The measured or calculated surface area of a human body using height and weight expressed as meters squared (M2).

Calibration: These are the markings or lines on the side of a syringe or cylinder which allow for correct measureable of amounts of liquids.

Calcium: an electrolyte abbreviated Ca or Ca2+.

Chloride: an electrolyte abbreviated Cl or Cl-.

Clark’s Rule: term used to describe procedure for calculating the amount of medication to administer based on the adult dose to a child aged 2-17 using the child’s weight in pounds.

Concentration: How much solute is dissolved in a certain amount of fluid.  This is going to be a specific amount of drug which is dissolved in a specific amount of fluid.  If the concentration is 20 mg/4 mL, for example, you will know that if your syringe holds 4mL of fluid, you also have 20 mg of drug in the syringe.

Conversion Factor: A fraction that relates one unit of measurement to another unit of measurement in a different measurement system.

Denominator: The number on the bottom portion of the fraction that represents the number of parts into which the whole is divided.

Dextrose: a type of carbohydrate often used in IV solutions to provide calories.

Diluent: Product added to a solution, powder, ointment, cream or other product used to reconstitute, dissolve, or dilute another product.

Dimensional Analysis: A problem-solving method based on the learning principles of continuity and repetition that provides a systematic way to set up dosage calculation problems that assists in identifying errors if the problem is set up incorrectly.

Dividing Line: The line separating the top portion or the fraction from the bottom portion of the fraction.

Divisor: In a / b = c, b is the divisor

Dose on Hand (DOH): The stock supply or the available dosage of medication that is on the shelf at the pharmacy or nursing station. Must always contain 2 pieces of information: how much drug and what holds that amount of drug. Example: 325 mg/tablet OR 325mg/mL. 

Dram: Common unit for volume in the apothecary measurement system. It is abbreviated as dr or 3. Its equivalent is 1 dr = 60 minims.

Drip Chamber: part of any IV tubing which allows visual inspection of fluid movement.  Drops of fluid can be seen falling in the drip chamber.

Drop: Abbreviated gtt. Its conversion factor is 1 gtt = 1 minim.

Drop Factor: calibration by a manufacture company of IV tubing.  The drop factor indicates how many drops of fluid falling in the drip chamber are equal to one milliliter of fluid. There is no universal drop factor. This calibration must be identified by the manufacturer for any set of IV tubing.  Examples of drop factors:  10gtts/ml; 15gtts/ml; 60gtts/ml.  If the information is simply written, “the drop factor is 10”, it is understood that 10 drops will equal one milliliter.

Electrolytes: an element or compound which can dissolve in water and is able to conduct an electric current. The usual unit of measure for electrolytes is a milliequivalent, or mEq. Some of the electrolytes and their abbreviations include:

Electronic Infusion Devices (EID's): an automated system of introducing a fluid other than blood into a vein. The device may have programmable settings that control the amount of fluid to be infused, rate, low-volume notification level, and a keep-vein-open rate. Some EIDs have titration modes that allow a change in the delivery rate without interrupting fluid flow. They also allow delivery in milliliters per hour.

Equivalent Unit: A unit that is similar to and contains an equal amount; used within a given measurement system.

Extemporaneous Compounding: The on demand and unanticipated preparation of a pharmaceutical product for a specific patient at the request of a precriber.

Fluid dram: Unit of volume, the fluid dram is defined as 1⁄8 of a fluid ounce, which means it is exactly equal to * 3.696 691 195 312 5 mL in the United States. Dram is also used informally to mean a small amount of liquid.

1 fluid dram = 5 mL = 1 teaspoon

Fluid dram symbol

fluid dram

Fluid ounce: Used in the apothecary and household system of measurement to measure fluid. It is abbreviated fl.oz or like a 3 with additional line. Its conversion factor is 1 fl.oz = 30 ml. symbol

Fluid Ounce symbol

fluid ounce

Fluid Resuscitation: the medical practice of replenishing bodily fluid lost through sweating, bleeding, fluid shifts from burns or other pathologic processes.

Fraction: A number that represents part of a whole number.

Frequency: This is how often something happens.  It may be how often you administer a dose of drug, or how often you hang an IV bag.  Never confuse the frequency with the infusion time.

Fried’s Rule:  term used to describe procedure for calculating the amount of medication based on the adult dose to administer to an infant or toddler of average height and weight based their age in months.

Given Quantity: The beginning point of the dimensional analysis problem; may be referred to as the dose on hand (DOH) or stock supply for conversion problems.

Grain: Common unit for weight used in the apothecary measurement system. It is abbreviated gr. Its conversion factor is 1 grain = 65 mg.

Half Normal saline: a 0.45% saline solution. It is called “half normal” because it has half the concentration of sodium and chloride as normal saline.

Hydration: pertaining to the amount of fluid in the body.

Household Measurement System: Measurement system commonly used in cookbooks and recipes, which uses whole numbers and fractions. It is considered the least accurate measurement system because of the differences between measuring devices.  It is also known as the U.S. Customary Measurement.

Infusion: The movement of fluid flowing into a patient.  Infusion time is how long it takes for the fluid to flow from the IV into the patient: Infusion rate is how quickly the fluid is moving.

IV Piggyback: abbreviated IVPB.  Usually refers to a smaller IV bag which is hooked onto a main IV line to intermittently dose IV medications. This technique means the patient does not have to have multiple venous catheters inserted.

Lactated Ringer’s solution: IV solution which contains the electrolytes Na, Cl, K and Ca plus lactate. The lactate serves as a buffer for acidosis. That is the lactate minimizes the change in the body’s pH. Abbreviated LRS.

Leading zero: Referred to as the additive identity. Used before a decimal notation to add emphasis to the presence of a decimal.

Liter: Base unit for volume in the metric system. It is abbreviated L. Its equivalent is 1 L = 1000mL.

Lund-Browder Chart:  term used to describe method for determining total body surface area for children and infants burned when using Parkland’s formula.

Main IV: generally refers to a patient’s the primary intravenous line. The main IV is usually fluid which is infusing continuously.

Matrix: A visual guide, similar to a tic-tac-toe board, used when performing alligation calculations.

Medication Reconstitution: Using the given directions, or recipe, on a prescription label to reconstitute the powder contained inside to a specific strength as indicated.

Metric Measuring System: A decimal system of weights and measures based on units of ten in which gram, meter, and liter are the basic units of measurement. The gram and the liter are used in medication administration.

Minim: An obsolete unit for volume in the apothecary measurement system. It is abbreviated as min or m. Its conversion factor is 1 minim = 1 gtt.

Nomogram Method: term used to describe procedure for calculating the amount of medication to administer to a pediatric patient based on their body surface area.

Normal saline: a 0.9% saline solution.  It is called “normal” because it has the same concentration of sodium and chloride as body fluids. It may be abbreviated NS.

Numerator: The number on the top portion of the fraction that represents the number of parts of the whole fraction.

Ounce: Used in the household measurement system to measure weight. It is abbreviated oz. Convertion 1oz = 30g.

Parkland’s Formula: term used to describe procedure for calculating the amount of fluid to administer a child for fluid resuscitation over the first 24 hours following a burn based on total body surface area and their weight.

Potassium: an electrolyte abbreviated K or K+.

Pound: Used as a measurement in the household measurement system mainly to determine body weight. It is abbreviated lb. Its equivalent is 1 lb = 16 oz and its conversion factor is 1 kg= 2.2 lb.

Reconstitution: The process of adding a diluent to a dry ingredient to make it a liquid.

Ringer’s solution: a type of IV fluid which contains the electrolytes Na, Cl, K and Ca.

Roman Numerals: A numeral system originating from Rome adapted from Etruscan numerals. Based on certain letters which are given values as numerals.

Saline solutions: a solution which contains the electrolytes sodium and chloride.

Shelf Life: The length of time medication can be stored safely and administered.

Scored Tablet: A tablet with one or two grooves that divides the tablet in half or in four quarter sections of equal size.

Sodium: an electrolyte abbreviated Na or Na+.

Tablespoon: Used as a measurement in the household measurement system. It is abbreviated as tbsp or T. Its conversion factor includes 1 Tbsp = 15 ml.

Teaspoon: Used as a measurement in the household measurement system. It is abbreviated as tsp or t. Its conversion factors include 1 tsp = 60 gtt = 5 ml.

Total Body Surface Area (TBSA):  is an assessment measure of burns of the skin. For children and infants, the Lund-Browder chart is used.

Total Fluid Volume/Time to Infusion.  The fluid volume must be in an IV bag and the infusion time must be the length of time it takes for that fluid amount to flow into the patient.  You will not infuse a fluid amount from a dose on hand vial, or the fluid amount you will add to the IVPB for a dose of a drug.

Titration: Technique by which we can determine the concentration of an unknown reagent using a standard concentration of another reagent that chemically reacts with the unknown. This standard solution is referred to as the "titrant". We have to have some way to determine when the reaction is complete that we are using. This is referred to as the "end point" or more technically the equivalence point. At that point all the unknown has been reacted with the standard titrant and some kind of chemical indicator must let us know when that point has been arrived at.

Unit Equivalent: Consists of the total number of partial units contained in a complete whole unit.

Unit Path: A series of conversions and/or equivalencies necessary to achieve the answer (wanted quantity) to the dimensional analysis (DA) problem.

Volume: Occupation of space that is quantified numerically; usually refers to liquid measurement.

Wanted Quantity: The answer to the dimensional analysis (DA) problem; may be referred to as the required dose to administer.

Weight: A measure of the heaviness of an object.

Young’s Rule: term used to describe one procedure for calculating the amount of medication based on the adult dose to administer to a child of average size based on the child’s age in years.


The following abbreviations may be used in written prescriptions:

Correct Dose - Measurement Abbreviations Correct Route - Route Abbreviations
g Gram IM Intramuscular
mg Milligram IV Intravenous
mcg Microgram IV PB Intravenous Piggyback
kg Kilogram IVP Intravenous push
L Liter SC Subcutaneous
mL milliliter IT Intrathecal
cc Cubic centimeter SL Sublingual
m Meter p.o. By mouth, orally
cm Centimeter A.D. Right ear
mm millimeter A.S. Left ear
grains Grain A.U. Both ears
dr, fluid dram Dram O.D. Right eye
oz, fluid ounce Ounce O.S. Left eye
fl fluid O.U. Both eyes
t, tsp Teaspoon pr per rectum
T, Tbsp Tablespoon vag vaginal
m Minim
gtt drop
c Cup
pt pint
qt quart
gal gallon

lb, #

U units
mEq milliequivalants

Correct Time - Frequency Abbreviations

a.c. Before meals
p.c. After meals
ad. lib. As desired, freely
p.r.n. When necessary
h.s. Hour of sleep, at bedtime
noc In the night
Stat Immediately, at once
ASAP As soon as possible
q Every
d Day, daily
q.d. Once a day, every day
q.o.d. Every other day
qam Every morning
qpm Every evening
b.i.d. Twice daily
t.i.d. Three times a day
q.i.d. Four times a day
q.h. Every hour
q.2h Every 2 hours
q. 3h Every 3 hours
q. 4h Every 4 hours
q. 6h Every 6 hours
q. 8h Every 8 hours
q. 12h Every 12 hours
min Minute
non rep Do not repeat
ud As directed
x Times


Correct Dosage Form - Dosage Form Abbreviations   Correct Drug - Common Drug Abbreviations
amp Ampule   APAP Acetaminophen
inj Injection   ASA Aspirin
tab Tablet   D5W 5% Dextrose in water
cap Capsule   D10W 10% Dextrose in water
cr Cream   NS Normal saline
ung, oint Ointment   H2O, aq Water
syr Syrup   SWFI Sterile water for injection
sol Solution   KCl Potassium Chloride
susp Suspension   NaCl Sodium Chloride
top Topical   MgSO4 Magnesium Sulfate
tinc Tincture   MSO4 Morphine Sulfate
trit Triturate   NTG Nitroglycerin
emul Emulsion   NSAID Non-steroidal anti-inflammatory drug
elix Elixir   PCN Penicillin
supp Suppository   PNV Prenatal Vitamin
      MVI Multivitamin

Be careful not to confuse MgSO4 and MSO4

General Abbreviations

ā Before
p After
c With
s Without
q Every
NPO Nothing by mouth
ss One half
d/c Discontinue
n & v Nausea and vomiting
qs Quantity sufficient
Sig Directions
Rx Prescription, recipe
NR No refills
dx Diagnosis
wt Weight
NKA No known allergies
NKDA No known drug allergies
OTC Over the counter
VO Verbal order
TO Telephone order
temp Temperature
°F Degrees Fahrenheit
°C Degrees Celsius
Greater than
Less than